Clinicoradiological Correlation of Infarct Patterns on Diffusion-weighted Magnetic Resonance Imaging in Stroke (original) (raw)
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Annals of …, 1997
Diffusion-weighted magnetic resonance imaging detects ischemic injury within minutes after onset, and has been used to demonstrate drug efficacy in animal models of stroke. In 50 patients diagnosed with acute ischemic stroke (<24-hour duration) within the middle cerebral artery territory, lesion volume was measured by diffusion-weighted imaging. Thirtyfour patients also had volumes measured by T2-weighted imaging chronically (median time, 7.5 weeks; mean, 15.9 weeks). Clinical severity was measured by the National Institutes of Health Stroke Scale Score and the Barthel index.
Diagnostic Accuracy of Diffusion Weighted Sequences of MRI in the Patients of Acute Brain Infarct
Diagnostic Accuracy of Diffusion Weighted Sequences of MRI in the Patients of Acute Brain Infarct, 2018
Stroke is typically the most frequent cause of disability and fth leading cause of death. In the past, early detection of acute brain infarct may be challenging for non-invasive diagnostic imaging, but recent advancement in diagnostic imaging makes it possible. Objective: To determine the diagnostic accuracy of diffusion weighted sequences of magnetic resonance imaging in the patients of acute brain infarct. Methods: In this cross-sectional study, among 70 patients of acute infarct were selected without age and gender discrimination by convenient sampling,
Annals of Neurology, 1997
Diffision-weighted imaging (DWI) detects small changes in water diffusion that occur in ischemic brain. This study evaluated the clinical usefulness of a phase-navigated spin-echo DWI sequence compared with T2-weighted magnetic resonance imaging (T2W MRI) in patients with cerebral ischemia and assessed apparent diffusion coefficient (ADC) and T2-weighted imaging (T2WI) changes over time. ADC values and T2 ratios of image intensity were measured from the region of ischemia and from the corresponding contralateral brain region. The clinical histories of patients with DWI scans obtained over the course of 1 year were reviewed to ascertain whether DWI aided in clinical diagnosis or management. Of 103 scans obtained a mean of 10.4 days after symptom onset, DWI detected six lesions not seen on T2WI and discriminated two new infarcts from old lesions. DWI was most useful within 48 hours of the ictus. The evolution of ADC values and T2 ratios was evaluated in 26 cases with known symptom onset times. ADC values were low at less than 1 week after stroke onset and became elevated at chronic time points. T2 ratios were near normal acutely, increasing thereafter. DWI was superior to T2W MRI in detecting acute stroke, whereas both techniques assisted in determining lesion age.
International journal of biomedical imaging, 2006
Diffusion- and perfusion-weighted magnetic resonance imaging (DWI and PWI) was applied for stroke diagnose in 120 acute (< 48 h) ischemic stroke patients. At hyperacute (< 6 h) stage, it is difficult to find out the infarction zone in conventional T1 or T2 image, but it is easy in DWI, apparent diffusion coefficient (ADC) map; when at 3-6-hour stage it is also easy in PWI, cerebral blood flow (CBF) map, cerebral blood volume (CBV) map, and mean transit time (MTT) map; at acute (6-48 h) stage, DWI or PWI is more sensitive than conventional T1 or T2 image too. Combining DWI with ADC, acute and chronic infarction can be distinguished. Besides, penumbra which should be developed in meaning was used as an indication or to evaluate the therapeutic efficacy. There were two cases (< 1.5 h) that broke the model of penumbra because abnormity was found in DWI but not that in PWI, finally they recovered without any sequela.
Journal of Neurology, Neurosurgery & Psychiatry, 2005
Background: Detection of multiple acute brain infarcts (MABI) by diffusion weighted magnetic resonance imaging (DWI) may provide information about stroke mechanism in (1) acute lacunar stroke, where evidence of MABI suggests a cause other than small artery disease (SAD), such as embolism or vasculitis (type 1 MABI); or (2) acute non-lacunar stroke, where MABI in the territory of at least two of the aortic branches supplying the brain indicates the presence of aortic or cardiac embolism rather than artery to artery embolism (type 2 MABI). Objective: To evaluate the prevalence of MABI and their impact on aetiological classification and prevention of stroke in patients with acute ischaemic stroke examined with DWI. Methods: 182 consecutive patients defined by DWI were evaluated. Stroke aetiology was classified according to the TOAST criteria, though ''lacunar stroke'' included patients with possible aetiologies other than SAD. Results: Type 1 MABI were detected in 21/72 patients (29%) with lacunar stroke, and type 2 MABI in 8/ 110 (7%) with non-lacunar stroke. A possible stroke mechanism different from SAD was found in nine type 1 MABI cases (43%): cardiac embolism (4); other determined aetiology (3); aortic embolism (2). Cardiac (2) or aortic (1) sources of embolism were detected in eight type 2 MABI cases. MABI patients with cardiac or aortic sources of embolism were treated with warfarin, the remainder with aspirin. Conclusions: Detection of type 1 MABI in patients with lacunar stroke improved diagnostic confidence and the choice of antithrombotic treatment. Further study is needed on stroke prevention in MABI cases caused by SAD alone.
Stroke, 2013
Background and Purpose— The accuracy of diffusion-weighted imaging (DWI) for the diagnosis of acute cerebral ischemia among patients with suspected ischemic stroke arriving to an emergency room has not been studied in depth. Methods— DWI was performed in 712 patients with acute or subacute focal symptoms that suggested an acute ischemic stroke (AIS), 609 of them with AIS. Results— DWI demonstrated a sensitivity of 90% and specificity of 97%, a positive likelihood ratio of 31 and a negative likelihood ratio of 0.1 for detecting AIS. The overall accuracy was 95%. Of those patients who demonstrated abnormal DWI studies, 99.5% were AIS patients, and of those patients with normal DWI studies 63% were stroke mimics. Conclusions— DWI is accurate in detecting AIS in unselected patients with suspected AIS; a negative study should alert for nonischemic conditions.
Neurological Research, 2011
Objective: We explored the relationship between predicted infarct core, predicted ischemic penumbras and predicted final infarct volumes obtained though apparent diffusion coefficient (ADC)-based method, as well as other clinical variables, and functional outcome. Methods: Patients with acute cerebral ischemic stroke were retrospectively recruited. The National Institutes of Health Stroke Scale score was evaluated at baseline and the modified Rankin Scale (mRS) at day 90. Favorable outcome was defined as an mRS score of 0 to 2, and unfavorable outcome as 3 to 6. Multimodal stroke magnetic resonance imaging was carried out at presentation. The volumes of diffusionweighted imaging (DWI) and perfusion-weighted imaging (PWI) were measured using the regions of interest (ROI) method. The volumes of predicted infarct core, predicted ischemic penumbra and predicted final infarct were obtained by an automated image analysis system based on baseline ADC maps. The association between baseline magnetic resonance imaging volumes, baseline clinical variables, and functional outcome was statistically analyzed. Results: The study included 30 males and 20 females (mean¡SD age, 56¡10 years). Baseline DWI, PWI and PWI-DWI mismatch volumes were not correlated with day-90 mRS (P.0.05). Predicted infarct core, predicted ischemic penumbra and predicted final infarct through ADC-based method were all correlated with day-90 mRS (P,0.05). A better outcome was associated with a smaller predicted volume. Low baseline National Institutes of Health Stroke Scale and recanalization also demonstrated a trend toward a favorable outcome. Receiver operating characteristic analysis showed that the area under the curve of predicted final infarct volume and recanalization were higher with statistical significance (P,0.001). Discussion: Predicted volumes obtained from ADC-based methods, especially predicted final infarct volume, as well as baseline National Institutes of Health Stroke Scale and recanalization may have effect on functional outcome in acute ischemic stroke.